X9455 Datasheet, PDF (7/18 Pages) Intersil Corporation – Dual Two-wiper Digitally-Controlled (XDCP) Potentiometer

X9455
Test Circuit
Test Point
R_W
Force
Current
Equivalent Circuit
R_TOTAL
R_H
C_H
C_W
R_L
C_L
R_W
Pin Descriptions
Bus Interface Pins
Serial Data Input/Output (SDA)
The SDA is a bidirectional serial data input/output pin for the
2-wire interface. It receives device address, operation code,
wiper register address and data from a 2-wire external
master device at the rising edge of the serial clock SCL, and
it shifts out data after each falling edge of the serial clock
SCL.
SDA requires an external pull-up resistor, since it’s an open
drain output.
Serial Clock (SCL)
This input is the serial clock of the 2-wire and Up/Down
interface.
Device Address (A2-A0)
The Address inputs are used to set the least significant 3 bits
of the 8-bit 2-wire interface slave address. A match in the
slave address serial data stream must be made with the
Address input pins in order to initiate communication with the
X9455. A maximum of 8 devices may occupy the 2-wire
serial bus.
Chip Select (CS)
When the CS pin is low, increment or decrement operations
are possible using the SCL and U/D pins. The 2-wire
interface is disabled at this time. When CS is high, the 2-wire
interface is enabled.
Up or Down Control (U/D)
The U/D input pin is held HIGH during increment operations
and held LOW during decrement operations.
DCP Select (DS1-DS0)
The DS1-DS0 select one of the four DCPs for an Up/Down
interface operation.
Hardware Write Protect Input (WP)
When the WP pin is set low, “write” operations to non volatile
DCP Data Registers are disabled. This includes both 2-wire
interface non-volatile “Write”, and Up/Down interface “Store”
operations.
DCP Pins
R_H0, R_L0, R_H1, R_L1
These pins are equivalent to the terminal connections on
mechanical potentiometers. Since there are two DCPs, there
is one set of R_H and R_L for each DCP.
R_W0A, R_W0B, R_W1A, and R_W1B
The wiper pins are equivalent to the wiper terminals of
mechanical potentiometers. Since there are two wipers per
DCP, there are four R_W pins.
7
FN8202.0
November 10, 2004